﻿using System;
using Xpedite.Extensions;
using Xpedite.Resources;
using Xpedite.Resources.Compressors;
using Xpedite.WebAbstraction;

/* Copyright (c) 2010 CBaxter
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 
 * IN THE SOFTWARE. 
 */

namespace Xpedite.Handlers
{
  internal class VirtualResourceHandler
  {
    private readonly ICompressorFactory _compressorFactory;

    public VirtualResourceHandler(ICompressorFactory compressorFactory)
    {
      Verify.NotNull(compressorFactory, "compressorFactory");

      _compressorFactory = compressorFactory;
    }

    public void ProcessRequest(IWebContext context)
    {
      IResourceCache cache = context.GetResourceCache();
      IResourceContainer resourceContainer = cache.Get(new ResourceUrl(context.Request));

      try
      {
        if (resourceContainer == null)
          context.Response.NotFound();
        else if (ResourceNotModified(context.Request, resourceContainer.Resource))
          context.Response.NotModified();
        else
          context.Response.SendResource(resourceContainer.Resource, _compressorFactory.Create(context.Request.Headers[WebRequestHeader.AcceptEncoding] ?? String.Empty));
      }
      catch
      {
        cache.Remove(new ResourceUrl(context.Request));
        throw;
      }
    }

    private static Boolean ResourceNotModified(IWebRequest request, IResource resource)
    {
      return String.Compare(request.Headers[WebRequestHeader.IfModifiedSince] ?? String.Empty, resource.LastModified.ToString(DateFormat.RFC1123), StringComparison.OrdinalIgnoreCase) == 0;
    }
  }
}
